I.d be sceptical that batteries are removed for road movements like this notwithstanding the load relief.
I have the current (pun intended) battery weight somewhere, will post when or if I find it.
Having been involved with shifting (fortuneately not the physical labour myself) lead acid cells of a similar amp hour capacity at static UPS sites, the job is massive. I might be wrong but I doubt the man hours costs of de-installing and then re-installing the cells from a battery loco would outweigh anything else. May as well pay the haulier.
I do have the battery weights from some other loks : the GNBPR 1B and 2B locos were 55 ton of which 31 is battery; think that gen came from Workhorses Of the London Underground; the modern day Clayton CDB90 (a.k.a. main line class 18) is 10 tonne Li battery.
I believe one of the modifications made in the recent rebuild of the battery locos is the the batteries are now in modules that can be quite easily removed by forklift truck. So it shouldn't be too hard to take them all out for transport if required.